Archive for September, 2011

There’s a lot of discussion about shellac. For such a simple product, it’s surprising how much “press” it gets in the repair forums.

The short description is that shellac is made from crushed bug stuff, mixed with denatured alcohol to make a finish for furniture. It’s been around a long time, and it’s been used in fountain pens from the early days. You find it all over the place under different names, like “confectioners glaze”. Yup, it’s used as a coating on candy. (if you don’t believe me, look it up!)

Pen people use it for all kinds of things like attaching sacs (sold as “sac cement”), securing sections and other things that you don’t want to move, stuff like that. It’s used because it’s reversible. Heat will soften it at around 103F, it’s not bothered by water (and therefore ink, which is why it’s used to attach sacs) and it can be removed easily with denatured alcohol… and it’s cheap. A half pint can bought at a hardware or paint store will cost something like $4-$5.

Now the fun stuff. Some people insist that for pen repair, you have to mix your own shellac, a 2 lb cut being preferable. Then some say that you have to use a certain grade or type of dried shellac is necessary. There was a time when I bought the fancy stuff at $10 for a little bottle, and $15 for a larger one. I can attest to the fact that it does stick well. It certainly worked to shellac the table cloth to the table at a pen show a few years ago. (ask me when you see me about that story)

But I abandoned the fancy stuff a few years ago. The truth is that I have never really found that much of a difference between the fancy stuff that you mix yourself and the basic Zinsser shellac from a can. The cheap stuff works, sacs stick. I do use both orange and blond shellac, the later for demonstrator 51 hoods so that the shellac doesn’t show up, and mix them on occasion. But I simply couldn’t justify the extra expense for the fancy “sac cement.”

But the real clincher for me was when I paid a visit to the Sheaffer Service Center in Ft. Madison with Richard Binder back in 2008. There on the floor, tucked behind the fountain pen repair station was… a gallon can of your basic hardware store variety Zinsser orange shellac. I figured that they had done a few more pen repairs than I have over the years, and if they thought it was the stuff to use, I needn’t argue.

It happened again today. I was working on a Mustard 51 that had a crack in the barrel, at the filler end (where else?), getting ready to do the first stage of blending the repair. I was installing the filler so that I could check the blind cap/barrel alignment and looked inside with a flashlight to make sure that the seat was smooth because the repair went across the threads and seat inside the barrel.

I won’t go into all of the details of the repair in this post – it’s enough to say that the pen had been repaired in the not too distant past and the sac was still still pliable, though twisted into a knot.

But whomever had done that repair had not done it right. There in the barrel, all of the way around was about an inch of dead diaphragm stuck to the barrel wall. The cleaning that I had done to remove it from the crack had not softened it one bit. It was stuck.

I see this quite often when a pen has been “repaired” by an amateur. Whether a sac pen or a vacumatic filled pen, it’s not uncommon to see the remains of the previous sac still stuck to the barrel wall, pressure bar or diaphragm. So why is that a such a bad thing?

For a sac pen there are a couple of problems. If stuck to the barrel wall, and/or the pressure bar, the old sac will reduce the inside diameter of the pen. The typical amateur will then grab a smaller sac, using in some cases a #16 where a 18 or 19 would be appropriate. This reduces the ink capacity significantly, and the sac has a tendency to slip off of the section because the sac has to be stretched too much. If it’s stuck to the section, the extra layer may make the section too big to fit into the barrel without force, and it keeps you from getting a good seal on the section.

In a Vacumatic filled pen remains of the old sac on the barrel wall can cause the diaphragm to bind as you press the plunger down to fill the pen. If the old diaphragm isn’t cleaned off of the seat in the barrel, you’ll have an extra layer (as if you had two diaphragms stacked one on top of the other). This will keep the filler from screwing into the barrel as far as it should. The pen can leak, and the blind cap may not screw down as far as it should. The typical amateur then tries to compensate by tightening the filler in even harder, which can cause barrel bulge or crack the barrel. I’ve seen it all, and it’s not pretty.

I know that it takes a little more work to get it ALL out, but it’s worth the effort.

I’ve been impressed with the infinite number of creative ways to fill a pen. There were of course serious motivations to avoid someone’s patent while coming as close as possible to copying another manufacturer’s ideas. Tom Zoss says that people followed the latest developments in pen technology just as much as we do with our smart phones today. Lawsuits abounded because big money was invested in each new development, and the manufacturers fiercely protected their “intellectual property.”

Once in a while you come across an odd duck that came out of someone’s evasive tactics. This past week I had an Osmia 94 cross the bench. I haven’t been able to find any documentation on the pens (yeh, repair guys read other repair guys books and web sites) but careful examination gives you some clues to how the pen was put together and how it fills.

Exhibit 1:

If some of the parts look familiar, may I suggest looking at a Parker Vacumatic pump? Rod down the middle, cone that slides over a rod, blind cap nut/nipple that fits over the cone, and a pin that goes through the back side of the cone to keep it in place on the rod. No evidence of a spring inside though, and the design in general precludes a spring up the middle of the rod as with a Vacumatic. The spring fits into the cup at the end of the rod, and the rod is held in the blind cap by the threaded brass nut. Even the angle of the taper on the cone matches that found on a Vacumatic pump. Inside the barrel, there should be a ring for the cone and diaphragm to seat against.

Like a Vacumatic, the 94 has a breather tube sticking out of the end of the feed, and the pen fills with successive strokes of the filler, the section screws in, and is sealed with a rosin based thread sealant.

So, how did it go together? Exhibit 2:

This view shows you the diaphragm in place – note the notch for the end of the diaphragm and the pellet to go through. The pin is in place, and rides down a slit on the other side of the rod. The only thing not attached yet is the blind cap. The diaphragm gets talc on the outside, and is folded back over the cone as with a Vacumatic. A spanner is used to screw the brass nut into the blind cap, and the blind cap nipple into the barrel.

Without a spring on the pump the action is not quite as elegant because the filler doesn’t bounce back on it’s own. You unscrew the blind cap, then using it as a knob you pump the filler up and down to fill the pen. Like a Vacumatic, it takes several strokes. When done, screw the blind cap back on, and wipe the ink off the nib.

I’ve been threatening to do this for some time now. Working by yourself at a bench, you have lots of time to think…. and you see a lot of interesting stuff crossing the bench that sets off a train of thought. So why not write about it?

There are few moments in a day when I don’t have at least some ink on my fingers. (I went to a doctors appointment a couple of years ago. The nurse looked at my hands and said “you have ink on your fingers.” “Well DUH! Do you know what I do for a living?” ) The computer is right behind me for easy information research, or writing.

So the “Blue Fingers Blog…” Ramblings about repairs, techniques, cool stuff that I’ve discovered or developed, maybe a political rant after listening to too much NPR, or stuff that I don’t dare say as a moderator on FPN.